Z90251 Datasheet, PDF (64/97 Pages) Zilog, Inc. – eZVision 200 Television Controllers with OSD

Z90255 ROM and Z90251 OTP
32 KB Television Controller with OSD
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Table 38 Master I²C Bus Interface Commands
Command Description
000
Send a Start bit followed by the address byte specified in the I²C data
register, then fetch the acknowledgment bit in I²C_DATA (0). Used to
initialize communication. Nine SCLK cycles are generated.
001
Send the byte of data specified in the I²C data register, then fetch an
acknowledgment bit stored in bit 0. Used in a Write frame. Nine SCLK
cycles are generated.
010
Send bit 7 of I²C_DATA register as an acknowledgment bit (ACK:
(0XXXXXXX), NAK: (1XXXXXXX)), then receive a data byte. Used in a
Read frame when the next data byte is expected. Nine SCLK cycles are
generated. Received data is read in the I²C data register.
011
Send bit 7 of I²C_DATA register as an acknowledgment bit (ACK:
(0XXXXXXX), NAK: (1XXXXXXX). Used in a Read frame. One SCLK
cycle is generated.
10X
Null operation. Must be used with a Reset bit.
110
Received one data byte. Used in a Read frame to receive the first data
byte after an address byte is transmitted. Eight SCLK cycles are
generated.
111
Send Stop bit. One SCLK cycle is generated.
PS001301-0800